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PACIFICO RESTAURANT - CONTINUING THE LEGACY McIntosh Timber Laminates, mlb Consulting Engineers & Timber Construction Solutions Ltd

Though it had been some time since Ken was involved directly with project work, he continued to play an active role in advising and providing guidance on options and solutions. The Pacifico project (formerly Ruby’s Restaurant) in Abu Dhabi, was a result of Ken’s earlier vision to see potential in the Middle East for McIntosh Glulam projects.

In the early 1990s on his way back from the opening of a project in North Africa, Ken visited Dubai, Kuwait and Bahrain looking at possible markets, visiting local consultants and contractors, leaving them with information on McIntosh Timber Laminates (MTL) solutions. MTLs first project came when a contractor recalled Ken’s visit and asked MTL to present a design for the Jumeirah Beach Club. This resulted in MTL providing the supply and supervision for this project in 1993. Pacifico is evidence of the continued business MTL have enjoyed since that time – all largely as a result of Ken’s pushing the boundaries of recognised markets in those days and seeing potential.

PROJECT DESCRIPTION

The design concept of a “floating” structure with dramatic curved profiles was developed by UK Architects Broadway Malyan for the Al Raha Beach Resort in Abu Dhabi. The curved structural elements particularly suited the use of glue-laminated timber, veering away from the region's common use of reinforced concrete. Mark L Batchelar Consulting Engineers was engaged to establish the feasibility of the concept by developing an initial timber structure system.

Based on this preliminary investigation Global Timber Homes Ltd, a joint venture between McIntosh Timber Laminates and Timber Construction Solutions, was successful in securing the construction contract. Detailed structural design was then progressed, maximising the use of New Zealand timber products. A total of ten container loads of New Zealand certified renewable resource timber was used in the project.

The main structural frames for the building envelope, first floor and deck areas are designed in glue-laminated radiata pine manufactured by McIntosh Timber Laminates Ltd, Auckland. Two intertwining trapezoids with curved corners are supported on turned Glulam columns up to 10 metres long. The first floor secondary framing is a truss joist system using Mitek parallel chord trusses. There is also a high level mechanical services concrete platform on slender concrete columns. This introduces an additional structural element to be integrated into the main building system comprising glue-laminated timber frames with plywood diaphragm roof, floor and wall elements.

The unusual geometry of the structure with asymmetry in both elevation and plan made a full three dimensional computer model of the structure essential. Structure loadings were based on British Standards for dead, live and wind loads while seismic design was required to comply with the American Unified Building Code UBC. The different structure elevations required wind load to be assessed for maximum loads on each of the four faces of the building.

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Plywood diaphragm roof panels being fixed to the main structural timber frames.

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Main structural timber elements of the first floor and the lower level roof above. Pairs of glue-laminated floor beams pass each side of circular timber columns to provide a large cantilevered deck.

All timber structural members were checked for adequate residual strength after fire while sustaining live load and reduced wind loads. In consideration of combinations of structure dead load, live load, wind load, seismic load and after fire stability a total of twenty independent load combinations needed to be reviewed.

A one hour fire resistance rating was required for the restaurant. This has been achieved through protection of the main structural timber members by sacrificial charring of the exposed sections and addition of a plaster board fire protected ceilings to the underside of both the roof and the floor systems.

Building construction took place on a reclaimed sand bank. As the building neared completion the sand was removed leaving the structure suspended over the water on concrete piles.

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INNOVATION

Connections between glue-laminated timber floor beams and round timber glue-laminated columns required an innovative approach. Substantial load transfer was required at these connections without reducing either column or beam capacity. Strength reduction of the beams and columns by notching or rebating was avoided by the development of curved steel collars screw fixed to the timber columns. The curved steel collar contains a large integrated steel shear pin that engages with a bearing seat plate screw fixed to the beams. The connection was easily installed and appropriate for both vertical and sloping timber columns. The curved brackets could be readily positioned on the columns to ensure that the shear pin was at the correct elevation to receive the floor beams.

540x135 Glulam Floor Beam

540x135 Glulam Floor Beam

M20 Bolts with 75Øx5 Washer

M20 Bolts with 75Øx5 Washer

318Ø Timber Column

318Ø Timber Column

14gx75 Type 17 Hex Head Screws

Curved Steel Plate to Column Connection

First Floor Beams to Timber Column Connection

3D View

3D View

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TIMBER DESIGN AWARDS 2010 CLEVER WOOD SOLUTIONS AWARD JOINT WINNER COMMERCIAL ENGINEERING EXCELLENCE AWARDHIGHLY COMMENDED

JUDGES’ COMMENTS

The structure for Ruby's Restaurant has a geometry that is asymmetrical in both elevation and plan, so the designers have had to consider a wide range of load combinations.

The resulting structure provides a complex but outwardly elegant solution to the client's needs. This building is a fantastic example of engineered wood from New Zealand in an international scale.